Four U.S. Patents which are related to the instant inventions disclosed herein are U.S. Pat. No. 6,997,910 B2, titled MULTI-CHAMBER SEQUENTIAL DOSE DISPENSING SYRINGE, filed May 3, 2004 and issued Feb. 14, 2006, to Michael Wallace Howlette, et al. (Howlette 910); U.S. Pat. No. 7,048,720 B1, titled MULTI-CHAMBER DOSE DISPENSING SYRINGE, filed Nov. 22, 2005 and issued May 23, 2006 to Gale H. Thorne, et al. (Thorne 720); U.S. Pat. No. 7,789,862 B2, titled MULTI-CHAMBER SEQUENTIALLY DISPENSING SYRINGE, filed Sep. 5, 2007 and issued Sep. 7, 2010 to Gale H. Thorne, Jr. (Thorne 862); and U.S. Pat. No. 7,101,354 B2, titled MIXING SYRINGE WITH AND WITHOUT FLUSH, filed Feb. 21, 2006 and issued Sep. 5, 2006 to Gale H. Thorne, Jr. (Thorne 354) et al.
Thorne (862) and Thorne (354) disclose backgrounds, uses and basic performance requirements of sequential dispensing and mixing syringes, respectively, and are hereby cited as reference for such. While the above cited art, and other art generally related, provide a basis for commercial devices, there are some basic operational criteria which are not completely met by any prior art. These criteria include:
For Sequentially Delivery Syringes                1. Utilization of a conventional syringe barrel and a pressure actuated valve disposed within the barrel to provide for dividing space within the barrel into two disparate chambers from which sequential delivery is to be accomplished.        2. Providing a pressure actuated valve which is fully closed by a plug which, until displaced, keeps the chambers divided and totally disparate.        3. Having a two stage valve which remains closed until after being cocked by a first action and then opened by a second action whereby a first action, such as employment of a pressure to open a valve, as, for example, in the case for devices made according to Thorne (720), is not available to cause an inadvertent and uncontrolled pressure caused flow through the valve and therefrom to a patient line upon opening.        4. Actuating a valve by a tactilely or other sensibly determinable pressure disposed upon the valve within the syringe barrel, that pressure being measurably and determinably greater than inherent pressure required to overcome valve to barrel wall friction which retards valve displacement within the barrel. Both the actuating pressure and inherent pressure originating by force disposed upon a syringe plunger rod such that a valve fully displaced into contact with the end of a syringe barrel is not inadvertently opened. Opening of the valve occurring after employing a force greater than the force required to produce the inherent pressure upon the plunger rod to cock actuation of the valve and then removing the force from the plunger rod to subsequently remove pressure from the valve to open the valve as pressure is removed therefrom, thus not producing an inadvertently and uncontrollably high dispensing flow upon valve opening.        
For Mixing Syringes                1. Utilization of a conventional syringe barrel and a pressure actuated valve disposed within the barrel to provide for dividing space within the barrel into two disparate chambers which are kept disparate until the valve is actuated.        2. Providing a valve which is fully kept closed by a plug, which, until opened by displacement of the plug, keeps chambers divided by the valve totally disparate.        3. Opening the valve by displacement of the plug only when pressure in the two chambers exceeds, by a predetermined pressure differential, a pressure originally contained within the pressure actuated valve.        
The instant invention disclosed herein, in appropriate embodiments, meets all of the above specified criteria.